title: Sorghum mutant RG displays antithetic leaf shoot lignin accumulation resulting in improved stem saccharification properties.
abstract: BACKGROUND
  Improving saccharification efficiency in bioenergy crop species remains an important challenge. Here, we report the characterization of a Sorghum (Sorghum bicolor L.) mutant, named REDforGREEN (RG), as a bioenergy feedstock.
  
  
  RESULTS
  It was found that RG displayed increased accumulation of lignin in leaves and depletion in the stems, antithetic to the trend observed in wild type. Consistent with these measurements, the RG leaf tissue displayed reduced saccharification efficiency whereas the stem saccharification efficiency increased relative to wild type. Reduced lignin was linked to improved saccharification in RG stems, but a chemical shift to greater S:G ratios in RG stem lignin was also observed. Similarities in cellulose content and structure by XRD-analysis support the correlation between increased saccharification properties and reduced lignin instead of changes in the cellulose composition and/or structure.
  
  
  CONCLUSIONS
  Antithetic lignin accumulation was observed in the RG mutant leaf-and stem-tissue, which resulted in greater saccharification efficiency in the RG stem and differential thermochemical product yield in high lignin leaves. Thus, the red leaf coloration of the RG mutant represents a potential marker for improved conversion of stem cellulose to fermentable sugars in the C4 grass Sorghum.
authors.affiliation: Plant Physiology, Department of Horticulture, Agricultural Science Center North, University of Kentucky, Lexington, KY 40546, USA. sdebo2@uky.edu.
authors.forename: Carloalberto
authors.initials: C
authors.lastname: Petti
authors.forename: Anne E
authors.initials: AE
authors.lastname: Harman-Ware
authors.forename: Mizuki
authors.initials: M
authors.lastname: Tateno
authors.forename: Rekha
authors.initials: R
authors.lastname: Kushwaha
authors.forename: Andrew
authors.initials: A
authors.lastname: Shearer
authors.forename: A Bruce
authors.initials: AB
authors.lastname: Downie
authors.forename: Mark
authors.initials: M
authors.lastname: Crocker
authors.forename: Seth
authors.initials: S
authors.lastname: Debolt